#include <iostream>
#include <string>
using namespace std;

class Fish
{
protected:
    bool FreshWaterFish;
public:
    Fish(bool ISFreshWater):FreshWaterFish(ISFreshWater){}
    void Swim()
    {
        if(FreshWaterFish)
            cout << "swims in lake" << endl;
        else cout << "swims in sea" << endl;
    }
};

class Tuna:public Fish
{
public:
   Tuna():Fish(false){}
};

class Carp:public Fish
{
public:
    Carp():Fish(true){}
};



int main(int argc, char const *argv[])
{
    Tuna mytuna;
    Carp mycarp;
    cout << "begin to print" << endl;
    mytuna.Swim();
    mycarp.Swim();
    /* code */
    return 0;
}


